One canonical word for a specced block of work — spec

Context

abcd organises engineering work in a layer it calls the spec — the how-to-build artefact, tracing back to an intent or a brief plumbing-phase (adr-1). abcd's terminology discipline exists to kill exactly one failure — the same concept named two ways — and the how layer is a load-bearing core noun: it appears in the terminology file, ADR titles and bodies, the reviews subsystem's identifiers, the JSON schemas, the reserved-vocabulary enum tokens in the brief, and prose across docs and READMEs.

Naming abcd's core artefact is a decision, not a content edit — ADRs are decision records, and the canonical noun is woven through schemas, lint, and the glossary. So the choice earns its own ADR.

Decision

abcd adopts spec as its single canonical word for a specced block of work — the how-to-build layer. It is abcd's native canonical noun; no other word names this concept on any abcd-owned surface.

• The terminology file terminology/core/spec.md defines the concept and carries forbidden_synonyms: [epic], so the glossary lint catches any regression to an older word.
• The spec_id field names the artefact in intent frontmatter and schemas.
• The reviews subsystem's identifiers and review-type tokens, the issue.schema.json / grill-report.schema.json keys and prose, the reserved-vocabulary enum tokens in brief/02-constraints/04-naming.md and their consumers, and prose across the brief, docs, command help, READMEs, and ADRs all say "spec".

The native spec layer (adr-26) is abcd's own store, so the canonical noun answers to abcd alone — there is no external tool whose vocabulary abcd must track and no vendored surface carved out of the rule.

This ADR amends adr-1, whose how layer is named "spec".

Alternatives Considered

1. A deprecated stub — a second term file pointing at spec.md. Rejected: a stub adds a file the glossary must explain — a mild violation of the one-canonical-term rule this decision exists to hold. A single clean term file is the honest move.
2. Two words for the layer — one schema field name, a different prose word. Rejected: this is the exact bilingual state the terminology discipline exists to end — the schema saying one word while the glossary and docs say another. Half a naming is worse than none; it makes the inconsistency permanent and load-bearing.
3. Leave the canonical noun implicit — no ADR, no forbidden-synonym guard. Rejected: without a guarded invariant, a future contributor reintroduces a synonym and it drifts in silently. The forbidden_synonyms entry turns the choice into a lint-enforced invariant, not a convention.

Consequences

Gains:

• abcd has one word for the how layer. The schema, the glossary, the reviews subsystem, the brief, and the docs all say "spec" — the same-concept-two-ways failure is closed for abcd's core noun.
• The forbidden_synonyms: [epic] entry in spec.md makes the choice a guarded invariant: the terminology lint flags any regression.

Costs / obligations:

• The forbidden-synonym guard must stay wired into the terminology lint, or the invariant decays to a convention.

Downstream decisions enabled:

• The terminology-lint guard means a future reintroduction of an older concept noun fails CI rather than drifting in silently.